For pregnant HIV-positive women who take antiretrovirals (ARVs) in the integrase inhibitor class, the fetal fraction test, a component of prenatal genetic testing, may not be as effective a screening tool as for other women, aidsmap reports. In a recent small study, those pregnant women with HIV who were taking integrase inhibitors had a lower mean fetal fraction (the amount of fetal DNA circulating in their plasma) than those who were not taking that class of ARVs.

Researchers analyzed data about 60 pregnant women who received noninvasive prenatal screening. Twenty of them were living with HIV. The women were an average of 30 to 31 years old. There were no major differences in demographic characteristics between the women with and without HIV, including BMI and ethnicity.

On the whole, the HIV-positive women had a higher mean fetal fraction than the HIV-negative women: 9.19 versus 8.24. However, this difference was not statistically significant, meaning it could have been driven by chance.

Among the HIV-positive women, those who were on integrase inhibitors at the time of their first prenatal visit had a lower mean fetal fraction than those who were not taking that class of ARVs: 5.5 versus 12.21. This difference was statistically significant. There was no such significant difference based on whether HIV-positive women took protease inhibitors.

The researchers believe their findings suggest that noninvasive prenatal screening may not be as effective a screening tool for women on integrase inhibitors compared with other women. They may not be able to get significant results from the screening.

To read the MedPage Today article, click here.